Sleepwalking isn't just a quirk of Homer Simpson and other cartoon characters who go on unconscious adventures. New research suggests it's even more common than you may think.

Researchers published a study in the journal Neurology involving more than 19,000 American adults, and found that nearly 30% had sleepwalked at some point in their lives. Far fewer said they experienced sleepwalking within the last year - only about 4% did. One percent had two or more episodes per month.

Dr. Maurice Ohayon of Stanford University and lead author of the study says sleepwalking can be risky business; some people can harm themselves or others while wandering about. Sleepwalking is far more likely to occur in childhood than adulthood; previous research suggests that as many as 30% of children have been affected.

Prior to this study, there was no good estimate of how many Americans sleepwalk generally, the researchers wrote. A study 10 years ago in Europe found a prevalence of 2%. And 30 years ago, a study in Los Angeles found about 2.5% of about 1,000 people experienced sleepwalking.

There wasn't a significant difference in sleepwalking in men vs. women, but the behavior did decrease with age, with the exception of those who reported it more than once per week.

Family history and genetics may play a role: 11.4% of people who reported sleepwalking said at least one sibling had episodes, compared to 7.8% of the rest of the participants. Individuals who said they sleepwalked in the previous year were more likely than others to have had a family history of sleepwalking.

The study authors also took into account participants' usage of medications for sleep, anxiety, depression and other purposes. They found that people who take a kind of antidepressant for anxiety called SSRI (selective serotonin reuptake inhibitor) had a higher likelihood of sleepwalking at least once per year. Those who took over-the-counter sleeping pills and tricyclic antidepressants were more likely to experience sleepwalking at least twice per month.

Sleep walking can be associated with bad sleep apnea. In my case I was a chronic sleepwalker since childhood. When I was finally studied in a sleep lab, they said I had no REM sleep at all. During REM sleep the muscles are frozen and dreams occur harmlessly. Without REM sleep, the person may act out their dreams, as I did. When I got a dental device and began side sleeping, my sleepwalking also stopped. I had the good fortune to own a house 500 feet from the road. I never sleep walked further than halfway. It is a frightening thing, another reason why sleep disorders should be diagnosed and treated.